Safety device for elevators



April 29, 1930. c. G. LUEHRMAN 1,756,370

SAFETY DEVICE FOR ELEVATORS Filed May 2'?, 1929 5 Sheets-Sheet l HUI fm mw i L -m'Il-IIIJ-Illllll gaas@ y @@azwhnwq April 29, 1930- I l c. G. LUEHRMAN 1,756,370

SAFETY DEVICE FOR ELEVATORS l l .36 i c??- Y, 35 Jg Aprilzs, 1930.

c. G. I UEHRMAN -1,756,370

SAFETY DEVICE FOR ELEVATORS Filed May 27, 1929 3 Sheets-Sheet 3 f l y lv UEU gg NEU Le# www Cima/"les @.wz/Qnzcuu z @kgfwf- Patented Apr. 29, 1930 UNITED STA CHARLES G. LUERMAN, F CHICAGO, ILLINOIS sAEETY DEVICE Eon ELEvAToEs Application Yfiled. May 27, 1929. Serial No. 366,119.

My present invention relates to improvements in safety devices for elevators and has special reference to the provision of facilities for preventing the fall of an elevator car should the supporting means be broken or its operation disorganized so that it fails to support the car.

I have had as ymy' principal object the provision of such facilities by means of a simple structure which may be economically manufactured; the securing of more direct and dependable operation, and the provision of a structure which may be vemployed without change in connection with a governor of usual type or 'a car supporting means of usual type independently or which may beassociated with bot-h of these elements at the same time so as to be actuated by either or both of them. f

As will'hereafterbe seen,'my invention may be embodied in a structure of relatively few and simple parts in such Ya manner that changes necessary for adapting it to shafts and cars rof different dimensions will require changes in but few of the parts involved in the construction.

I have attained the foregoing objects and results by means of the'structure illustrated in the yaccompanying drawings in which#- Fi-g. 1 is an elevation of a structure embodying my invention shown in its relation to the elevator shaft, elevator car and supporting means before it "has been-operated to prevent the fall ofthe elevator. o

Fig. 2 is a view similar to Fig. 1 except that the view is of the structure after it has been operated to prevent the fall ofthe car.

Fig. 3 is a vertical longitudinal section of the structure in the position shown in Fig. 1.

Fig. 4 is a vertical longitudinal section of the structure in the position shown in Fig. 2.

Fig. 5 is a transverse section on line 5-5 of Fig. 4.

Fig. 6 is a top plan ofthe structure.

Fig. 7 is a longitudinal horizontal section of the structure on line 7e-7, Fig. 1, and

Fig. 8 is an .end viewof'the structurelooking into a pair of the clamping jaws.

Similar reference characters referto sim- 59 ilar parts throughout the several views.

I have shown my invention embodied in and carried by an overhead beam with depending angles or brackets for securing the same to the uprights of the elevator or car. rih'is overhead beam, as most clearly shown in Figs. 1, 2, 5 and 8, consistsl of sidechannels 10 and 11, spaced apart and secured together by a number of transverse top and bottom plates, bolted to the flanges of the respective channels. The end top cross plates 12-12 are centrally recessed in their outer edges yat 13 for the passage of the flange of the guide rails 14. The bottom end plates 15 are provided on their outer ends with depending flanges or plates 16 which are secured =to the uprights of they car or elevator'l?. The outer edges of the platesl do not extend quite to the'plane of the guide rails and there is therefore no necessity of providing them with such slots as 13 provided in the top plates.l

-Pivoted between the top and bottom endp'la'tes upon substantial pivot bolts 18ya-re the two guide rail gripping jaws 19.19, as most clearly shown in Figs. 6 and 7. The meeting edges at the outer ends of the gripping jaws are slotted, asat 20, so as to `more easily accommodate 'the rail '14 when the gripping jaws-are `'in open position, as sho-wn lin 6. The gripping faces of the slots'13 may advantageously be armoured -with face plates v21 i of high speed steel or other suitable material. It is often vunnecessary to have the gripping j-aws of a length equal to'the width of the'channels 10, in Iwhichcase the additional space is occupied by abearing-block orshim 2-2,located between the channels 10 and uponthe bottom end plates 115. rIhe inner portionsof the gripL ping jaws behind A'the plane of the pivots 18-18 need not be as wide as the 'gripping ends, as shown in 3 and 4,' and these parts are also tapered longitudinally.

The entire structure is supported from the top center plate 23 through the instrumentality of the spring 2,4, washer 25, nut 26 and bolt 27, which 'connects with the c'levis 29 to which the supporting cables lare attached. Thereis ne bottom center plate but in place 'thereof are `bolted journals 30 supporting crank shafts-31, to the centers of which are fixed by pinsor set screws,vor in-any suitable manner,

supporting dogs 32, the purpose of which will hereafter appear.

On one end of the crank shafts 31 are pinned, or otherwise secured, the cranks 33 which are in horizontal position, as shown in Fig. 1, when the dogs are in substantially vertical position, as shown in Fig. 3, and which are independing position, as shown in Figs. 2 and 4, when the supporting dogs 32 are in horizontal position, as shown in Fig. 4.

Between the center .and end transverse plates are top and bottom intermediate trailsverse plates. The intermediate top transverse plates 34 and 35 are perforated adjacent their outer edges to permit the passage of the wedge rods or bolts 36 madeintegral with which or attached to the lower ends thereof, are wedges 37, most clearly seen in Figs. 3, 4 and 5. These wedges are adapted, when released, to be drawn between the rear arms of the clamping bars 19-19 by expansion springs 33 extending between the upper intermediate plates 34 and 35 and nuts 39on the upper ends of the wedge rods. The

- jaws 19, as most clearly shown in Fig. 5, are

mitred or beveled at the points 19L where the wedge 37 enters between them and at the lower edges of the mitred portion are provided semi-elliptic bores to receive anti-friction rollers 19h. This construction provides immediate, direct and powerful instrumentalities for causing the clamping aws to clamp the o'uide rails.

The wedges 37 are maintained in non-op erative position by the instrumentalities now to be described. Located beneath the inner portions of the top intermediate transverse plates 34 and 35 are bottom intermediate transverse plates 40, and secured between the top and bottom intermediate transverse plates are the squared columns 41, to the opposite lateral faces of which are pivoted the lever arms 42. Between the outer ends of the lever arms 42 are pivoted the bottoms of the wedges 37 which are squared to permit of such pivoting, and between the inner ends of the lever arms 42 are secured by pins or otherwise blocks 43 which rest upon the dogs 32 when these dogs are standing in vertical position, as shown in Fig. 3. l/Vhen the blocks 43 are supported by the dogs 32 the wedges 37 are held against the action of the springs 33 against entry between the clamping jaws 19. Whenthe dogs 32 are in horizontal position, as shown in F ig. 4, the supports against the action of the springs 39 are removed and the wedges 37 are drawn between the clamping jaws, thereby causing them to grip the rails 14.

The means for automatically moving the dogs from vertical to horizontal positions is as follows.: The intermediate top cross plate 35 is provided with a depending flange 44 which extends below the Harige of the adjacent channel. Pivoted to the depending flange 44 is a trigger lever arm 45, the inner end of which is provided with an enlargement or hammer head 46 coming immediately above the inner ends of both of the crank arms 33, when these crank arms are in horizontal position. The trigger lever arm 45 is extended laterally suliciently far to engage with a thimble 47 on the lgovernor cable 48, if it be desired to operate the mechanism through a governor. Such a governor attachment, however, need not be employed as l attach to the trigger arm 45 a link 49 which attaches to one end of a lever arm 50 pivoted upon a bracket 51 secured to the flanges of the channels. The inner end of the lever arm 50 is bent to come under the clevis 29 so that upon failure of the cables to support the car the clevis will be drawn downward by the action of the spring 24 and the trigger lever arm operated through the link 49 and lever arm 50 to throw the crank arms 33 into vertical position and the dogs 32 out of supporting position. A light coil spring 52- extending between the trigger lever arm 45 and the lower flange of the adjacent channel serves to hold the trigger arm yieldingly in inoperative position.

ln order to adapt my structure to different sizes of elevator shafts and cars it is only necessary to change the lengths of the channels 10 and 11and the lengths of the lever armsV 45 and 50 and to carry in stock rights and lefts of the top intermediate transverse plates 35.

Local regulations often determine the presence of governors in elevator constructions and freight elevators are seldom required to be provided with such equipment. In any contingency, however, my invention may be readily employed with but trilling differences in expense of either manufacture or installation.

Having described ,my invention what I claim as new and desire to secure by Letters Fatent is 1. An elevator safety device comprising a cross beam, pairs of gripping jaws pivoted in the endsthereof, spring actuated wedges movable transversely between the opposite ends of said jaw members, lever arms pivoted to said wedges, dogs for supporting said levers to maintain said wedges in inoperative position, crank shafts carrying said dogs, a lever coactively related to the cranks of said crank shafts and extending to the location of the path of the governor .cable of the elevator, and a second lever arm linked to said first lever and extending into coactive relation to the means for supporting said car.

2. An elevator safety device comprising a cross beam, pairs of gripping jaws pivoted in the ends thereof, spring actuated wedges movable transversely between the opposite ends of said jaw members, lever arms pivoted to said wedges, dogs for supporting said levers to maintain said wedges in inoperative position,

crank shafts carrying Said dogs, a lever coactively related to the crank of said crank shafts and extending to the location of the f path of the governor cable of the elevator.

3. An elevator safety device comprising a cross beam, pairs of gripping jaws carried thereby, spring actuated means for actuating said jaws, levers for supporting said springs against operation, crank shafts and dogs for holding said levers, and a lever arm for actuating said crank shafts.

4. An elevator safety device comprising a cross beam, pairs of gripping jaws carried thereby, spring actuated means for` actuating said jaws, levers for supporting said springs against operation,r crank shafts and dogs for holding said levers, and a lever arm extending from the cranks of said crank shafts, and a second lever arm linked to said last mentioned arm and extending into coactive relation with the means for supporting the elevator. f

CHARLES G. LUEHRMAN. 

